Patek Philippe

A friend bought a PP, a rather expensive one on line. he found the watch in brand new condition, but to his surprise the serial number was filed! Can he service the watch in PP AD?

Mindara, If your "friend" is in the U.S., he may be committing a felony by accepting and possessing this watch. There is no reason anyone would file off theserial number from a Patek other than to conceal the origin of a stolen watch. Park

So what should he do when they refused to give him his money back?

because noone would do that, even an AD that was heavily discounting.. they would just not stamp the papers/etc.. sounds to me like was stolen before hitting the store.. or maybe stolen from courier and then filed to conceal origin... which model is it?